1. Field of the Invention
The present invention generally relates to communications networks, and more specifically to aggregation of links between nodes of the same peer group into a logical link and aggregation of the topology of border nodes of a child peer group into a logical star topology.
2. Description of the Related Art
As described in the ATM Forum Private Network-Network Interface Specification Version 1.0, topology aggregation is the notion of reducing nodal as well as link information to achieve scaling in a large network. It is not only motivated by the need for complexity reduction but also to hide the topology internals of peer groups in the interest of security.
However, if topology aggregation is performed by network nodes individually with no regard to their neighbor nodes, all network nodes would provide aggregation with different levels of approximation. Such internodal variability would result in inefficient operation of the network.
It is therefore an object of the present invention to provide an efficient communication network by using an agreed-upon parameter for topology aggregation.
According to a first aspect of the present invention, there is provided for a communication network a network node which comprises negotiating means for exchanging aggregation parameters with a neighbor node to agree on a negotiated aggregation parameter, link aggregating means for aggregating a plurality of physical links between the network node and a neighbor node into a logical link according to the negotiated aggregation parameter, a database for storing resource data of the logical link, and means for exchanging the resource data with the neighbor node and updating contents of the database with resource data of the neighbor node.
Each of the physical links is represented by a resource vector and its element is represented by a resource value of a different resource class, and the logical link is represented by a resource vector and its element is represented by a sum of a maximum resource value, multiplied by the aggregation parameter, of the elements of the resource vectors of the physical links and a minimum resource value, multiplied by unity minus the aggregation parameter, of the elements of the resource vectors of the physical links.
In order to optimize the link aggregation, the network node preferably further comprises link performance evaluation means for evaluating an operating performance of the logical link by using traffic data from the network, and update means for updating the negotiated aggregation parameter according to the detected operating performance. The negotiating means is arranged to exchange the updated aggregation parameter with the neighbor node to agree on a negotiated updated aggregation parameter and the link aggregating means uses the negotiated updated parameter for aggregating the physical links into the logical link.
According to a second aspect, the present invention provides a peer group leader node of a peer group in a communication network in which a plurality of interconnected nodes are divided into a plurality of peer groups, each peer group having border nodes via which it is interconnected with other peer groups and the peer groups forming a parent peer group. The peer group leader node comprises negotiating means for exchanging aggregation parameters with other peer group leader nodes to agree on negotiated aggregation parameters, topology aggregating means for aggregating physical topology of the border nodes of the peer group into a logical star topology using the negotiated aggregation parameters, a database for storing resource data of the logical star topology, and routing means for exchanging the resource data with a neighbor peer group leader node and updating the database with resource data from the neighbor peer group leader node.
In order to optimize the topology aggregation, the peer group leader node preferably further comprises star topology performance evaluation means for evaluating an operating performance of the star topology by using traffic data from the network, and update means for updating the negotiated aggregation parameters according to the evaluated operating performance. The negotiating means is arranged exchange the updated aggregation parameters with other peer group leader nodes to agree on negotiated updated aggregation parameters, and the topology aggregating means is arranged to aggregate the physical topology using the negotiated updated aggregation parameters.
According to a third aspect, the present invention provides a communication network comprising a plurality of network nodes organized into a plurality of interconnected peer groups, each of the peer groups having a peer group leader node and a plurality of border nodes through which the at least one peer group is connected to other peer groups. Each network node comprises negotiating means for exchanging aggregation parameters with a neighbor node of the same peer group to agree on a negotiated aggregation parameter, link aggregating means for aggregating a plurality of physical links between the network node and a neighbor node into a logical link according to the negotiated aggregation parameter, a database for storing resource data of the logical link, and means for exchanging the resource data with the neighbor node and updating contents of the database with resource data of the neighbor node. Each group leader node comprises negotiating means for exchanging aggregation parameters with other peer group leader nodes to agree on negotiated aggregation parameters, topology aggregating means for aggregating physical topology of the border nodes of the peer group into a logical star topology using the negotiated aggregation parameters, a database for storing resource data of the logical star topology, and routing means for exchanging the resource data with a neighbor peer group leader node and updating the database with resource data from the neighbor peer group leader node.